package com.hmdp.service.impl;

import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONObject;
import cn.hutool.json.JSONUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.entity.Shop;
import com.hmdp.mapper.ShopMapper;
import com.hmdp.service.IShopService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.CacheClient;
import com.hmdp.utils.RedisData;
import com.hmdp.utils.SystemConstants;
import io.lettuce.core.GeoRadiusStoreArgs;
import org.springframework.data.geo.*;
import org.springframework.data.redis.connection.RedisGeoCommands;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.jdbc.core.RowCallbackHandler;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;

import java.time.LocalDateTime;
import java.util.*;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.stream.Stream;

import static com.hmdp.utils.RedisConstants.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class ShopServiceImpl extends ServiceImpl<ShopMapper, Shop> implements IShopService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private CacheClient cacheClient;

    @Override
    public Result queryById(Long id) {
        //缓存穿透
//        Shop shop = cacheClient
//                .queryWithPassThrough(CACHE_SHOP_KEY, id, Shop.class, this::getById, CACHE_SHOP_TTL, TimeUnit.MINUTES);
        //互斥锁解决缓存穿透
//        Shop shop = queryWithMutex(id);
        //逻辑过期解决缓存击穿
        Shop shop = cacheClient.queryWithLogicExpire(CACHE_SHOP_KEY, id, Shop.class, this::getById, 20L, TimeUnit.SECONDS);
        if (shop == null) {
            return Result.fail("店铺不存在！");
        }
        return Result.ok(shop);
    }
//    private static final ExecutorService CACHE_REBUILD_EXECUTOR = Executors.newFixedThreadPool(10);

/*    public Shop queryWithLogicExpire(Long id){
        String key = CACHE_SHOP_KEY + id;
        String shopJson = stringRedisTemplate.opsForValue().get(key);
        if (StrUtil.isBlank(shopJson)){
            return null;
        }
        RedisData redisData = JSONUtil.toBean(shopJson, RedisData.class);
        Shop shop = JSONUtil.toBean((JSONObject) redisData.getData(), Shop.class);
        LocalDateTime expireTime = redisData.getExpireTime();
        if (expireTime.isAfter(LocalDateTime.now())){
            return shop;
        }
        String lockKey = LOCK_SHOP_KEY + id;
        boolean isLock = tryLock(lockKey);
        if (isLock){
            CACHE_REBUILD_EXECUTOR.submit(()->{
                try {
                    this.saveShopToRedis(id,20L);
                } catch (Exception e) {
                    throw new RuntimeException(e);
                } finally {
                    unlock(lockKey);
                }

            });
        }
        return shop;
    }*/

/*    public Shop queryWithMutex(Long id){
        String key = CACHE_SHOP_KEY + id;
        String shopJson = stringRedisTemplate.opsForValue().get(key);
        if (StrUtil.isNotBlank(shopJson)){
            return JSONUtil.toBean(shopJson, Shop.class);
        }
        if(shopJson != null){
            return null;
        }

        String lockKey = LOCK_SHOP_KEY + id;
        Shop shop = null;
        try {
            boolean isLock = tryLock(lockKey);
            if (!isLock){
                Thread.sleep(50);
                return queryWithMutex(id);
            }
            shop = getById(id);
            Thread.sleep(200);
            if (shop == null){
                stringRedisTemplate.opsForValue().set(key,"",CACHE_NULL_TTL,TimeUnit.MINUTES);
                return null;
            }
            stringRedisTemplate.opsForValue().set(key, JSONUtil.toJsonStr(shop),CACHE_SHOP_TTL, TimeUnit.MINUTES);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        } finally {
            unlock(lockKey);
        }
        return shop;
    }*/

/*    public Shop queryWithPassThrough(Long id){
        String key = CACHE_SHOP_KEY + id;
        String shopJson = stringRedisTemplate.opsForValue().get(key);
        if (StrUtil.isNotBlank(shopJson)){
            return JSONUtil.toBean(shopJson, Shop.class);
        }
        if(shopJson != null){
            return null;
        }
        Shop shop = getById(id);
        if (shop == null){
            stringRedisTemplate.opsForValue().set(key,"",CACHE_NULL_TTL,TimeUnit.MINUTES);
            return null;
        }
        stringRedisTemplate.opsForValue().set(key, JSONUtil.toJsonStr(shop),CACHE_SHOP_TTL, TimeUnit.MINUTES);
        return shop;
    }*/

/*    private boolean tryLock(String key){
        Boolean flag = stringRedisTemplate.opsForValue().setIfAbsent(key,"1",LOCK_SHOP_TTL, TimeUnit.SECONDS);
        return BooleanUtil.isTrue(flag);
    }

    private void unlock(String key){
        stringRedisTemplate.delete(key);
    }
*/
    public void saveShopToRedis(Long id,Long expireSecond) throws InterruptedException {
        Shop shop =getById(id);
        Thread.sleep(100);
        RedisData redisData =new RedisData();
        redisData.setData(shop);
        redisData.setExpireTime(LocalDateTime.now().plusSeconds(expireSecond));
        stringRedisTemplate.opsForValue().set(CACHE_SHOP_KEY+id,JSONUtil.toJsonStr(redisData));
    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public Result update(Shop shop) {
        Long id = shop.getId();
        if (id == null) {
            return Result.fail("店铺id不能为空！");
        }
        updateById(shop);
        String key = CACHE_SHOP_KEY + shop.getId();
        stringRedisTemplate.delete(key);
        return Result.ok();
    }

    @Override
    public Result queryShopByType (Integer typeId, Integer current, Double x, Double y) {
        if (x == null || y == null) {
            Page<Shop> page = query()
                    .eq("type_id", typeId)
                    .page(new Page<>(current, SystemConstants.DEFAULT_PAGE_SIZE));
            return Result.ok (page.getRecords ());
        }
        int from = (current - 1) * SystemConstants.DEFAULT_PAGE_SIZE;
        int end = current * SystemConstants.DEFAULT_PAGE_SIZE;
        String key = SHOP_GEO_KEY + typeId;
        Point center = new Point (x, y);
        Distance d = new Distance (5000);
        Circle circle = new Circle (center, d);
        GeoResults<RedisGeoCommands.GeoLocation<String>> results = stringRedisTemplate.opsForGeo ()
                .radius (
                        key,
                        circle,
                        RedisGeoCommands.GeoRadiusCommandArgs.newGeoRadiusArgs ()
                                .includeDistance ()
                                .limit (end)
                );
        if (results == null) {
            return Result.ok (Collections.emptyList ());
        }
        List<GeoResult<RedisGeoCommands.GeoLocation<String>>> list = results.getContent ();
        if (list.size () <= from) {
            return Result.ok (Collections.emptyList ());
        }
        List<Long> ids = new ArrayList<> (list.size ());
        Map<String, Distance> distanceMap = new HashMap<> (list.size ());
        list.stream ().skip (from).forEach (result -> {
            String shopIdStr = result.getContent ().getName ();
            ids.add (Long.valueOf (shopIdStr));
            Distance distance = result.getDistance ();
            distanceMap.put(shopIdStr, distance);
        });
        String idStr = StrUtil.join (",", ids);
        List<Shop> shops = query().in ("id", ids).last ("ORDER BY FIELD (id," + idStr + ")").list ();
        for (Shop shop : shops) {
            shop.setDistance(distanceMap.get(shop.getId().toString()).getValue());
        }
        return Result.ok (shops);
    }
}
